The most common adverse reactions (≥20%) with Tucatinib in combination with trastuzumab and capecitabine in patients with metastatic breast cancer are diarrhea, palmar-plantar erythrodysesthesia, nausea, hepatotoxicity, vomiting, stomatitis, decreased appetite, anemia, and rash.
The most common adverse reactions (≥20%) with Tucatinib in combination with trastuzumab in patients with unresectable or metastatic colorectal cancer are diarrhea, fatigue, rash, nausea, abdominal pain, infusion related reactions, and pyrexia.
from FDA,2023.01